Webster

The Webster Field CO₂-EOR project is located in Harris County, Texas, along the Texas Gulf Coast within the Gulf Coast Basin. The field produces primarily from Frio Formation sandstone reservoirs, consisting of shallow-marine to deltaic depositional systems characterized by stacked channel and barrier-bar sands with variable permeability and stratigraphic trapping. Webster Field was originally discovered in the early twentieth century and developed through conventional primary production followed by secondary recovery techniques before conversion to tertiary recovery using CO₂ injection. CO₂ flooding was implemented to recover residual oil remaining after waterflood depletion by achieving miscible or near-miscible displacement within the sandstone reservoir intervals. Injection is conducted through pattern flood configurations, often incorporating water-alternating-gas (WAG) cycles to control mobility and improve sweep efficiency in heterogeneous sand bodies. Produced CO₂ is separated at surface facilities, recompressed, and recycled for reinjection, while retained volumes contribute to long-term geologic storage within the reservoir system. The project is connected to Gulf Coast CO₂ infrastructure networks supplying industrial or naturally sourced CO₂ to EOR operations. As with most CO₂ floods, operations are designed to extend field life, increase ultimate recovery, and retain a portion of injected CO₂ through structural, residual, and dissolution trapping mechanisms. CO₂ floods typically operate for decades, with repeated injection cycles progressively trapping additional volumes of CO₂ in the reservoir.